Fire injection engines



F. A. BOUDREAUX PIRE INJECTION ENGINES Sept. 29, 1959 Filed May 17, 1957 FIG.I

' 2 SheetsSheet 1 FIG.2

INVENTOR.

Frahcis A.Boudreaux Sept. 29, 1959 Filed May 17, 1957 FIG.5

F. A. BOUDREAUX FIR INJECTION ENGINES 2 SheetsSheet 2 INVENTR.

FrancisA.Boudreaux 2,906,254: FIRE INJECTION NGINES Francs Addison Bdudreaux, Sterling, Va.

Application May 17, 1957, Serial No. 659,995

14 Claims. 7 (Cl. 123-143) This invention relates to internal combustion engines and pertains more particularly to certain improvements therein whereby the electric spark ignition system is eliminated by utilizing an auxiliary compression ignition mechanism which is of small volume but which is exhausted in such manner as to ignite the cylinder gases in proper timed relationship with the positioning of the crai1kshaft.

Of primary concern in connection with this invention is the provision of compression ignition means carried by the working piston et the internal combustion engine, which compression ignition means takes the form of an auxfliary piston and cylinder assembly operated in timed relationship to the position of the main or working piston within the cylinder for inducting a small charge of fuelair mixture and compressing it to a high degree and thereby igniting such small inducted charge by compression and which auxiliary piston cylinder incorporates exhaust means operating in timed relationship so as to discharge the products of combustion from the auxiliary cylinder into the main or working cylinder of the engine at or near the top of the compression stroke of the main or working piston to thereby ignite the main fuel-air charge.

Another object of this invention is to obviate the necessity for a precsely controlled fuel-air ratio which is required as, for example, in electric spark ignition engines in order to assure proper firing and combustion. V In the present invention, the auxiliar piston and cylinder operate at extremely high compression capable of firing and bmning almost any fuel-air mixture which may be present in the main cylinder with the exhausted products of combustion of the auxiliary cylinder being ignited by compression and with such compression being great enough to cause the products of combustion to burn at a temperature suificient to ignit substantially any fuelair mixture ratio within the main or working cylinder,

thereby eliminating the necessity for closely controlled fuel-air mixture ratios.

An object of this invention ancillary to the above resides in the provision of an improved type of internal combustion engine which obviates the necessity for throttling the incming air and thereby the power delivered by the engine may be controlled only by varying the amount of fuel delivered to the cylinder or cylinders of the engine, thereby 'assuring greater eflciency by virtue of the fact that the cylinders will not be subjected to low manifold pressures as is the case in conventional spark ignition engines and whereby, as a result, the engines fuel consumption will be greafly reduced by the added expansion of the added air.

A further object of this invention is to provide an improved type of internal combustion engine incorporating a working piston operating Within Working cylinder and an auxiliary piston operating with an auxiliary cylinder forming a compression ignition unit and said unit fitted in the crown of the main opworking piston, the

United Statcs Patent O 2,906,254 Patented Sept. 29, 1959 auxiliary piston being cam operated in conjunction with the connecting'rod operating the working piston.

Another object of this invention is to provide improvements in internal combustion engines wherein cam mechanism is fOrmed at the'piston end of the connecting rod operating the working piston et the engine, which cam mechanism actuates an auxiliary piston operating within an auxiiiary cylinder forming a compression ignition unit fitted directly in the working piston and wherein the cam operati0n is such as to operate the auxiliary piston in timed relationship with the positioning of the Working piston Within its cylinder in which it operates so as to discharge the products' of combustion et theauxfliary piston and cylinder assembly into the main cylinder at or near the top of the compression stroke of the work ing piston to thereby eliminate the necessity for any other mixture igniting means for the working cylinder.

Another object of this invention is to provide a device of the character described in which the igniting device is formed from a relatively few parts and wherein the construction thereof is maintained as simple as is possible while yet permitting the device to achieve the objectives thereof.

Another object of this invention is to provide improvements in internal combustion engines whereby the spark ignition system is entirely eliminated and wherein the carbureting system is greatly simplified so as to reduce the cost of manufacturing the engines and their component parts.

A further object'of this invention is to provide certain improvements in internal'combustion engines to rende'r the same more efficient in operation by permitting the engine to operate on a wide range of fuel-air ratio mixturc.

' Another object of this invention is to provide an improved type of internal combustion engine in which starting, particularly in extremely cold weather, is positive and wherein the engine will operate 'at maximum efficiency and power when cold.

. Another object of this invention is to provide an improved form of internal combustion engine wherein the ignition of the main or working charge is accomplished by means of the ignition of a small volume of the initially inducted charge, under very high temperature from very high compression and discharging the same into the main charge in proper timed relationship with the operation et the engine so as to fire the main charge at the proper time.

A furtherobject ofthis invention is to provide an improved type of internal combustion engine employing an igniting mechanism contained Within the crown of the working piston or pistons as the case may be, which unit is of simple form and cam operated and which is removable by merely removing the cylinder head of the engine and without requiring removal of the oil pan thereof.

In the drawings:

Fig. 1 is a partial sectional view taken through a working piston constructed in accordance with the invention and illustrating the auxiliary piston and cylinder assembly associated therewith and further illustrating the means by which the'upper end 'of the connecting rod is operative to actuate the auxiliary piston;

"Fig. 2 is a vertical section taken through the wris pin and the center of the auxfliary piston shown in Fig. 1 and illustrating further details of the construction of both the 'upper end of the connecting rod' and of the auxiliary piston and cylinder assembly;

. Figs. 3 and 4 are sectional vieWs illustrating the actuation of the-cam mechanism and illustrating the connectirig rod in various positions;

Fig. 5 is an enlarged sectional view taken through the auxiliary cylinder illustrating details of its construction;

Fig. 6 is an enlarged sectional view taken through the auxiliary piston and illustrating details of the discharge port therein;

Fig. 7 is an enlarged partial section illustrating the formation of the surface of the auxiliary piston in cooperation with the walls of the auxiliary cylinder;

Fig. 8 is an enlarged sectional vieW similar to Fig. 6 but illustrating a modified form of auxiliary piston construction; and

Fig. 9 is a side elevational view of the modified piston illustrated in Fig. 8.

Referring now more particularly to Fig. 1, the reference numeral 10 indicates in general et connecting rod having a wrist pin boss 11 at the upper end thereof receiving a conventional wrist pin 12 and by means of which the upper end of the connecting rod is articulated to the piston indicated generally by the reference character 13 having the usual skirt 14 and a crown 15. In the center of the piston crown 15 there is provided an opening having internal thrcads 16 in the upper portien thereof and presenting a step or shoulder 17 in the lower region thereof, substantially as is shown. Received within this opening and projecting completely therethrough is an auxiliary cylinder and piston assembly indicated generally by the reference character 18.

The cylinder is best shown in Fig. 5 and will be seen to include a lower portion 19 provided with external fins 20 for cooling purposes as more clearly described hereinafter and having an enlarged head end 21 having an annular flange 22 presenting a downwardly facing annular surface 23 which is adapted to scat in opposition to the previously mentioned shoulder 17 in the bore through the piston crown 15. A sealing gasket 24 is used between the head end portion of the cylinder and the shoulder 17 in the piston crown 15 to prevent leakage of gases through the piston crown and there additionally may be provided shims 25, the purpose of which will be presently apparent.

The lower end 19 of the cylinder is provided with diametrically opposed slots 26 extending from the lower edge 27 thereof to an upper point 28 to provide clearance for the auxiliary piston wrist pin hereinafter described.

The head end of the cylinder is provided with an exhaust passageway 29 which extends from the intermediate point 30 in the cylinder bore 31 up to the dorme 32 on the upper surface of the head end of the cylinder and which dome is provided with radially extending ports 33 for discharging products of combustion through the passageway 29 and into the working cylinder of the associated internal combustion engine. The cylinder is also provided with an intake passageway 34 extending from a point 35 up through the head end of the piston and opening as at 36 in the upper surface thereof.

The auxiliary piston indicated generally by the reference character 37 is shown most clearly in Fig. 6 and will be seen to include a cylindrical slug 38 provided in its lower region with a transverse bore 39 for receiving the wrist pin 40 theref0r, see particularly Figs. 1 and 2, and which slug is provided with an exhaust passageway 41 leading from the point 42 at the crown of the piston slug 38 to a point 43 opening through the side thereof.

The auxiliary piston wrist pin 40 has its opposite end portions riding within the cam slots 44 formed in the cam ears 45 and 46 which are integral with the wrist pin boss 11 of the connecting rod 10 and which cam slots are formed in a particular manner, as hereinafter more fully described, to cause a predetermined reciprocatory motion of the piston 37. The outer surface of the piston 37 is provided with annular grooves 47 to provide a seal within the cylinder bore 31 since the piston 37 carries no sealing rings, the grooves 64 being of such shape in cross section as to hold a film of oil therewithin to eect a sealing and lubricating between the cylinder bore and the auxiliary piston.

The cam ears 45 and 46 straddle the lower end 19 of the cylinder with the wrist pin 40 projecting through the slots 26 in the opposite side of the cylinder and permitting vertical motion of the wrist pin 40 under the action of the cam slots 44. In this respect, it is to be noted that the cam slot 44 includes an upper arcuate portion 48 and an upwardly inclined lower portion 49. The juncture 50 of these portions is substantially at the centerline of the connecting rod 10 as indicated by the dotted line 51 and as the working piston is reciprocated under the action of the connecting rod 10, the rocking motion imparted to the upper end of the rod as is shown more clearly in Figs. 3 and 4 will effect a timed reciprocation of the auxiliary piston 37 within the cylinder bore 31 in such manner and in such timed relationship that When the working piston 13 is coming up on its compression stroke, the auxiliary piston 37 will first be withdrawn downwardly within its associated cylinder bore 31 during the first of crank rotation on the compression stroke of the working piston 13 and will reach its lowermost position about 70 before the top of the compression stroke. During the final 70 of crank rotation on the compression stroke of the working piston 13, the auxiliary piston 37 will be moved from its lowermost position within cylinder bore 31 to its uppermost position therewithin, substantially as is shown in Fig. 1 of the drawings. When the piston 37 is in the position shown in Fig. 4, the intake passageway 34 will be open to permit the fuel-air mixture in the main working cylinder to be forced into the space above the auxiliary piston 37 and when the auxiliary piston 37 has reached its uppermost position as shown in Fig. 1 of the drawings, the exhaust passageway 41 therewithin will match up with the exhaust passageway 29 in the auxiliary cylinder to thus discharge the highly compressed small charge of fuel-air mixture through the exhaust ports 33 and which fuel-air mixture, due to the high degree of compression which it has received within the auxiliary cylinder,wfll be burning at a high temperature and expanding at a rapid rate so as to shoot out tongues of burning gas from the various exhaust ports 33 radially in all directions in the working cylinder to completely and substantially simultaneously ignite all of the fuelair mixture contained therewithin, thereby achieving a very efiicient, complete and substantially instantanecus combustion of the compressed fuel-air mixture in the working cylinder.

In the form of the invention shown in Figs. 79, the piston 55 incorporates an exhaust passageway 56 opening upon the side of the piston at 57 and in the region of the crown thereof at 58. The piston is provided with a pluraliy of ring grooves 59, 60, 61 and 62 within which piston rings 63 are fitted, as shown. The ring lands of the piston are provided with circumferential grooves as indicated by reference character 64 for the purpose of holding oil therein and helping to maintain the compression and the exhaust port opening 57 is surrounded by circular grooves 65 and 66 so as to seal off this area of the piston and prevent blowby on the compression stroke of the auxiliary piston.

If desired, the exhaust passageways 41 in the auxiliary piston as well as the exhaust passageways 29 in the Working piston may be coated as indicated respectively by numerals 70 and 71 with ceramic or other suitable material having good heat and oxidation resistant properties to prevent these passageways from being enlarged and burned out by the extremely hot gases passing therethrough.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, and since the scope of the invention -is defined by the appended claims, ail changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly coopera tive equivalents are theretore intended to be embraced by those claims.

I claim:

1. In an internal combustion engine, an engine block having a cylinder therein, a piston reciprocable within said cylinder and having a connecting rod articulted thereto for efiecting the reciprocation of said piston, said piston having an auxiliary cylinder therein and there being an auxiliary piston reciprocable within said auxiltioned piston communicating the crown thereof with an intermediate portion of said auxiliary cylinder and there being an exhaust passageway in said auxiliary cylinder communicating with an intermediate portion thereof and communicating with the first mentioned cylinder through the crown of said first piston, said auxiliary piston being reciprocable within the auxiliary cylinder between a lowermost position in which the intake passageway is uncovered and an uppermost position, said auxiliary cylinder having an exhaust passageway therein communicable with the exhaust passageway in the first piston when the auXiliary piston is in an uppermost position within said auxiliary cylinder, and means for reciprocat ing said auxiliary piston in timed relationship to the reciprocatory motion of said first piston.

2. In an internal combustion engine including a cylinder block having a cylinder bore fornied therein, a working piston reciprocable within said cylinder bore, said working piston having an auxiliary cylinder therein, an auxiliary piston reciprocated within said auxiliary cylinder, said working piston carrying a wrist pin and there being a connecting rod having a small end journalled on said wrist pin, means connecting the upper portion of said connecting rod to said auxiliary piston for reciprocating the same in timed relationship with the reciprocation of said working piston, there being an intake passageway leading to said auxfliary cylinder, and there being an exhaust passageway leading from said auxiliary cylinder through the top of'said working piston for discharging burning gases into the working cylinder at or near the top of the compression stroke of the working piston.

3. In an ignition system for internal combustion engines having a working cylinder, a working piston reciprocable within said working cylinder and a connecting rod articulated to said working piston, a small volume cylinder in the head of said working piston and having an exhaust passageway leading from such auxiliary cylinder to discharge ports formed in the top of said working piston, an auxiliary piston reciprocahle within said auxiliary cylinder and connected to said connecting rod for reciprocation thereby in timed relation to the reciprocatien of said working piston, there being an intake passageway from an intermediate portion of said auxiliary cylinder leading to the top of said working piston whereby a small portion of fuel-air mixture drawn into sa1d working cylinder may be inducted into said auxfl1ar cylinder above said auxiliary piston, and means for discharging the fuel-air mixture compressed by said auxrl iary piston into and through said exhaust passageway.

4. In an internal combustion engine, an engine block having a cylinder therein, a piston reciprocable within said cylinder and having a connecting rod articulated thereto for efiecting the reciprocafion of said piston, satd piston having an auxiliary cylinder therein and there being an auxfliary piston reciprocable within said auxiliary cylinder, an intake passageway within the first mentioned piston communicating the crown thereof with an intermediate portion of said auxiliary cylinder and there being an exhaust passageway in said auxiliary cylinder communicating with an intermediate portion thereof and communicafing with the first mentioned cylinder through the crown of said first piston, said auxiliary p15- ton being reciprocable within the auxiliary cylinder between a lowermost position in which the intake passageway, is uncovered and having an exhaust passageway therein communicable with the exhaust passageway in the first piston when the auxiliary piston is in an uppermost position within said auxiliary cylinder, and means for reciprocating said auxiliary piston in timed relationship tothe reciprocatory motion of said first piston, the upper end of said connecting rod having cam slots therein, a pin received in said cam slots and projecting through said auxiliary piston to efiect the recipr fiafion thercof in response to rocking motion of the connecting rod.

5. In an internal combustion engine including a cylinder block having a cylinder bore formed therein, a working piston reciprocable within said cylinder bore, said working piston having an auxiliary cylinder therein, an auxiliary piston reciprocated within said auxiliary cylinder, said working piston.carrying a wrist pin and there being a connecting rod having a small end journalled on said wrist pin, means connecting the uppei portion of said connecting rod to said auxiliary piston for reciprocaflng the same in timed relationship with the reciprocation of said working piston, there being an intake passageway leading to said auxiliary cylinder, and there being an exhaust passageway leading from said auxiliary cylinder through the top of said working piston for discharging burning gases into the working cylinder at or near the top of the compression stroke of the work ing piston, the upper end of said connecting rod having cam slots therein, a pin received in said cam. slots and projecting through said auxiliary piston to eiect the reciprocation thereor in response to rocking motion of the connectng rod.

6. In an ignition system for internal combustion en gines having a working cylinder, a working piston reciprocable within said working cylinder and a connecting rod articulated to said working piston, a small volume cylinder in the head of saidworking piston and having an exhaust passageway leading from such auxiliary cylinder to discharge ports formed in the top of said working piston, an auxiliary piston reciprocable within said auxiliary cylinder and connected to said connecting rod for reciprocation thereby in timed relation to the reciprocation of said working piston, there being an intake passageway from an intermediate portion of said auxiliary cylinder leading to the top of said working piston whereby a small portion of fuel-air mixture drawn into said working cylinder may be inducted into said auxi]iary cylinder above said auxiliary piston, and means for discharging the fuel-air mixture compressed by said auxiliary piston into and through said exhaust passageway, the upper end of said connecting rod having cam slots therein, a pin received in said cam slots and projecting through said auxiliary piston to efiect the reciprocafion thereof in response to rocking motion of the connecting rod.

7. In an internal combustion engine, a cylinder block having a cylinder bore therein, a working piston reciprocable within said cylinder bore, a crankshaft actuated connecting rod, said connecting rod having an upper end portion articulated to said working piston, said working piston having an auxiliary cylinder therein immediately above the point of articulation between the connecting rod and working piston, an auxiliary piston received within said auxiliary cylinder, said upper end of the connecting rod having a pair of upstanding cam cars rigid therewith, said auxiliary piston having a skirt portion received between said cam cars and said cam ears being provided with cam slots theren, a pin carried by the skirt of said auxiliary piston and projecting within said cam slots in the cam cars whereby rocking motion of the connecting rod imparts reciprocatory motion to said auxiliary piston in timed relationship to the reciproca tien of said working piston, there being an intake passageway leading to said auxiliary cylinder, and there being au exhaust passageway leading from said auxiliary cylinder through the top of said working piston for discharging 7 burning gases into the working cylinder at or near the top of the compressionflroke of the working piston.

8. In an internal combustion engine, a cylinder block having a cylinder bore therein, a working piston reciprocable within said cylinder bore, a crankshafi actuated connecting rod, said connecting rod having an upper end por tien articulated to said Working piston, said working pis ton having an auxiliary cylinder therein immediately above the point of articulation between the connecting rod and working piston, an auxiliary piston received within said auxiliary cylinder, said upper end of the connecting rod having a pair of upstanding cam cars rigid therewith, said auxiliary piston having a skirt portion received between said cam cars and said cam cars being provided with cam slots therein, a pin carried by the skirt of said auxiliary piston and projecting within said cam slots in the cam cars whereby rocking motion of the connecting rod imparts reciprccatory motion to said auxiliary piston in timed relationship to the reciprocation of said working piston, an intake passageway leading from an intermediate portion of said auxiliary cylinder to the top of said working piston, an exhaust passageway extending from an intermediate portion of said auxiliary cylinder to the top of said working piston, said auxiliary piston having an exhaust passageway therein leading from the top thereof to an intermediate portion thereof and being aligned with said exhaust passageway in the auxiliary cylinder when the auxiliary piston is at top dead center of its stroke and the top of said auxiliary piston uncovenng the intake passageway at bottom dead center of its stroke, and means for directing fuel-air mixture compressed and ignited within said auxiliary cylinder when said auxiliary piston is at top dead conter, radially within the first mentioned cylinder above the top of said working piston.

9. The assembly as defined in and by claim 8 wherein said cam slots include arcuate upper portions having their center of curvature coincidental with the point of pivotal connection between the connecting rod and its associated crankshaft and a lower portion inclined upwardly toward and intersecting the upper portions thereof.

10. The assembly as defined in and by claim 8 wherein said auxiliary piston is circumferentially grooved and Wherein there are annular grooves surrounding the opening of said exhaust passageway at the skirt of said auxiliary piston.

11, The assembly as defined in and by claim 9 wherein the point of intersection between the stated two portions of the cam slots intersects the center line of the connecting rod.

12. The assembly as defined in and by claim 9 wherein the point of intersection between the stated two portions of the cam slots intersects the center line of the connecting rod, and wherein said auxiliary piston is circumferentiaily grooved and there are annular grooves surrounding the opening of said exhaust passageway at the skirt of said auxiliary piston.

13. In an internal combustion engine including a cylinder block having a cylinder bore formed therein, a Working piston reciprocable within said cylinder bore, said working piston carrying a wrist pin and there being a connecting rod having a small and journalled on said wrist pin, a fire injection unit removably mounted in said working piston, said unit including an auxiliary cylinder, an auxiliary piston reciprocable within said auxiliary cylinder, means connecting the upper portion of said connecting rod to said auxiliary piston for reciprocating the same in timed relationship with the reciprocation of said working piston, there being an intake passageway leading to said auxiliary cylinder, and there being an exhaust passageway leading from said auxiliary cylinder through the top of said working piston for discharging burned gases into the working cylinder at or near the top of the compression stroke of the working piston.

14. The assembiy as defined in and by claim 13 wherein said auxiliary cylinder is provided with cooling fins.

References Cited in the file of this patent UNITED STATES PATENTS 1,696,060 Smith Dec. 18, 1928 2,297,823 Barnes Oct. 6, 1942 2,369,792 Notturno Feb. 20, 1945 2,394,269 Svete Feb. 5, 1946 

